greenfoot
Class Greenfoot
java.lang.Object
greenfoot.Greenfoot
public class Greenfoot extends java.lang.ObjectThis utility class provides methods to control the simulation and interact with the system.
Greenfoot类提供模拟和系统交互的方法，非常关键。
Key names
Part of the functionality provided by this class is the ability to retrieve keyboard input. The methods getKey() and isKeyDown() are used for this and they return/understand the following key names:
所有这些功能中最主要的是能捕捉键盘和鼠标动作的方法--getKey（）和isKeyDown（）
•"a", "b", .., "z" (alphabetical keys), "0".."9" (digits), most punctuation marks. getKey() also returns uppercase characters when appropriate.
•"up", "down", "left", "right" (the cursor keys)
•"enter", "space", "tab", "escape", "backspace"
•"F1", "F2", .., "F12" (the function keys)
Version:
2.1
Author:
Davin McCall
构造方法
Constructor Summary Greenfoot()
具体方法：
Method Summary static void delay(int time) 延迟现有动作time步后执行
Delay the current execution by a number of time steps.
static java.lang.String getKey() 捕捉按下的键盘的字母或符号名
Get the most recently pressed key, since the last time this method was called.
static MouseInfo getMouseInfo() 捕捉鼠标的状态
Return a mouse info object with information about the state of the mouse.
static int getRandomNumber(int limit) 得到0-limit之间的随机数
Return a random number between 0 (inclusive) and limit (exclusive).
static boolean isKeyDown(java.lang.String keyName) 检查keyName健是否被按下
Check whether a given key is currently pressed down.
static boolean mouseClicked(java.lang.Object obj) 检查对象obj是否被鼠标点击又释放
True if the mouse has been clicked (pressed and released) on the given object.
static boolean mouseDragEnded(java.lang.Object obj) 检查鼠标对对象obj的拖拽是否停止
True if a mouse drag has ended.
static boolean mouseDragged(java.lang.Object obj) 检查对象obj是否被鼠标拖拽
True if the mouse has been dragged on the given object.
static boolean mouseMoved(java.lang.Object obj) 检查鼠标是否移动到对象obj上
True if the mouse has been moved on the given object.
static boolean mousePressed(java.lang.Object obj) 检查对象obj是否被鼠标点击
True if the mouse has been pressed (changed from a non-pressed state to being pressed) on the given object.
static void playSound(java.lang.String soundFile) 播放soundFile音乐文件
Play sound from a file.
static void setSpeed(int speed) 设置全部对象的运行速度
Set the speed of the execution.
static void start() 开始执行
Run (or resume) the execution. static void stop() 结束执行
Pause the execution.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
Greenfoot
public Greenfoot()Method Detail
getKey
public static java.lang.String getKey()Get the most recently pressed key, since the last time this method was called. If no key was pressed since this method was last called, it will return null. If more than one key was pressed, this returns only the most recently pressed key.
Returns:
The name of the most recently pressed key
isKeyDown
public static boolean isKeyDown(java.lang.String keyName)Check whether a given key is currently pressed down.
Parameters:
keyName - The name of the key to check
Returns:
True if the key is down
delay
public static void delay(int time)Delay the current execution by a number of time steps. The size of one time step is defined by the Greenfoot environment (the speed slider).
See Also:
setSpeed(int)
setSpeed
public static void setSpeed(int speed)Set the speed of the execution.
Parameters:
speed - The new speed. the value must be in the range (1..100)
stop
public static void stop()Pause the execution.
start
public static void start()Run (or resume) the execution.
getRandomNumber
public static int getRandomNumber(int limit)Return a random number between 0 (inclusive) and limit (exclusive).
playSound
public static void playSound(java.lang.String soundFile)Play sound from a file. The following formats are supported: AIFF, AU and WAV.
The file name may be an absolute path, a base name for a file located in the project directory or in the sounds directory of the project directory.
Parameters:
soundFile - Typically the name of a file in the sounds directory in the project directory.
Throws:
java.lang.IllegalArgumentException - If the sound can not be loaded.
mousePressed
public static boolean mousePressed(java.lang.Object obj)True if the mouse has been pressed (changed from a non-pressed state to being pressed) on the given object. If the parameter is an Actor the method will only return true if the mouse has been pressed on the given actor. If there are several actors at the same place, only the top most actor will receive the press. If the parameter is a World then true will be returned if the mouse was pressed on the world background. If the parameter is null, then true will be returned for any mouse press, independent of the target pressed on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been pressed as explained above
mouseClicked
public static boolean mouseClicked(java.lang.Object obj)True if the mouse has been clicked (pressed and released) on the given object. If the parameter is an Actor the method will only return true if the mouse has been clicked on the given actor. If there are several actors at the same place, only the top most actor will receive the click. If the parameter is a World then true will be returned if the mouse was clicked on the world background. If the parameter is null, then true will be returned for any click, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been clicked as explained above
mouseDragged
public static boolean mouseDragged(java.lang.Object obj)True if the mouse has been dragged on the given object. The mouse is considered to be dragged on an object if the drag started on that object - even if the mouse has since been moved outside of that object.
If the parameter is an Actor the method will only return true if the drag started on the given actor. If there are several actors at the same place, only the top most actor will receive the drag. If the parameter is a World then true will be returned if the drag action was started on the world background. If the parameter is null, then true will be returned for any drag action, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been dragged as explained above
mouseDragEnded
public static boolean mouseDragEnded(java.lang.Object obj)True if a mouse drag has ended. This happens when the mouse has been dragged and the mouse button released.
If the parameter is an Actor the method will only return true if the drag started on the given actor. If there are several actors at the same place, only the top most actor will receive the drag. If the parameter is a World then true will be returned if the drag action was started on the world background. If the parameter is null, then true will be returned for any drag action, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been dragged as explained above
mouseMoved
public static boolean mouseMoved(java.lang.Object obj)True if the mouse has been moved on the given object. The mouse is considered to be moved on an object if the mouse pointer is above that object.
If the parameter is an Actor the method will only return true if the move is on the given actor. If there are several actors at the same place, only the top most actor will receive the move. If the parameter is a World then true will be returned if the move was on the world background. If the parameter is null, then true will be returned for any move, independent of the target under the move location.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been moved as explained above
getMouseInfo
public static MouseInfo getMouseInfo()Return a mouse info object with information about the state of the mouse.
Returns:
The info about the current state of the mouse. Or null if nothing has happened with the mouse since it was last checked.
Class Greenfoot
java.lang.Object
greenfoot.Greenfoot
public class Greenfoot extends java.lang.ObjectThis utility class provides methods to control the simulation and interact with the system.
Greenfoot类提供模拟和系统交互的方法，非常关键。
Key names
Part of the functionality provided by this class is the ability to retrieve keyboard input. The methods getKey() and isKeyDown() are used for this and they return/understand the following key names:
所有这些功能中最主要的是能捕捉键盘和鼠标动作的方法--getKey（）和isKeyDown（）
•"a", "b", .., "z" (alphabetical keys), "0".."9" (digits), most punctuation marks. getKey() also returns uppercase characters when appropriate.
•"up", "down", "left", "right" (the cursor keys)
•"enter", "space", "tab", "escape", "backspace"
•"F1", "F2", .., "F12" (the function keys)
Version:
2.1
Author:
Davin McCall
构造方法
Constructor Summary
Greenfoot()
具体方法：
Method Summary
static void delay(int time) 延迟现有动作time步后执行
Delay the current execution by a number of time steps.
static java.lang.String getKey() 捕捉按下的键盘的字母或符号名
Get the most recently pressed key, since the last time this method was called.
static MouseInfo getMouseInfo() 捕捉鼠标的状态
Return a mouse info object with information about the state of the mouse.
static int getRandomNumber(int limit) 得到0-limit之间的随机数
Return a random number between 0 (inclusive) and limit (exclusive).
static boolean isKeyDown(java.lang.String keyName) 检查keyName健是否被按下
Check whether a given key is currently pressed down.
static boolean mouseClicked(java.lang.Object obj) 检查对象obj是否被鼠标点击又释放
True if the mouse has been clicked (pressed and released) on the given object.
static boolean mouseDragEnded(java.lang.Object obj) 检查鼠标对对象obj的拖拽是否停止
True if a mouse drag has ended.
static boolean mouseDragged(java.lang.Object obj) 检查对象obj是否被鼠标拖拽
True if the mouse has been dragged on the given object.
static boolean mouseMoved(java.lang.Object obj) 检查鼠标是否移动到对象obj上
True if the mouse has been moved on the given object.
static boolean mousePressed(java.lang.Object obj) 检查对象obj是否被鼠标点击
True if the mouse has been pressed (changed from a non-pressed state to being pressed) on the given object.
static void playSound(java.lang.String soundFile) 播放soundFile音乐文件
Play sound from a file.
static void setSpeed(int speed) 设置全部对象的运行速度
Set the speed of the execution.
static void start() 开始执行
Run (or resume) the execution.
static void stop() 结束执行
Pause the execution.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
Greenfoot
public Greenfoot()Method Detail
getKey
public static java.lang.String getKey()Get the most recently pressed key, since the last time this method was called. If no key was pressed since this method was last called, it will return null. If more than one key was pressed, this returns only the most recently pressed key.
Returns:
The name of the most recently pressed key
isKeyDown
public static boolean isKeyDown(java.lang.String keyName)Check whether a given key is currently pressed down.
Parameters:
keyName - The name of the key to check
Returns:
True if the key is down
delay
public static void delay(int time)Delay the current execution by a number of time steps. The size of one time step is defined by the Greenfoot environment (the speed slider).
See Also:
setSpeed(int)
setSpeed
public static void setSpeed(int speed)Set the speed of the execution.
Parameters:
speed - The new speed. the value must be in the range (1..100)
stop
public static void stop()Pause the execution.
start
public static void start()Run (or resume) the execution.
getRandomNumber
public static int getRandomNumber(int limit)Return a random number between 0 (inclusive) and limit (exclusive).
playSound
public static void playSound(java.lang.String soundFile)Play sound from a file. The following formats are supported: AIFF, AU and WAV.
The file name may be an absolute path, a base name for a file located in the project directory or in the sounds directory of the project directory.
Parameters:
soundFile - Typically the name of a file in the sounds directory in the project directory.
Throws:
java.lang.IllegalArgumentException - If the sound can not be loaded.
mousePressed
public static boolean mousePressed(java.lang.Object obj)True if the mouse has been pressed (changed from a non-pressed state to being pressed) on the given object. If the parameter is an Actor the method will only return true if the mouse has been pressed on the given actor. If there are several actors at the same place, only the top most actor will receive the press. If the parameter is a World then true will be returned if the mouse was pressed on the world background. If the parameter is null, then true will be returned for any mouse press, independent of the target pressed on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been pressed as explained above
mouseClicked
public static boolean mouseClicked(java.lang.Object obj)True if the mouse has been clicked (pressed and released) on the given object. If the parameter is an Actor the method will only return true if the mouse has been clicked on the given actor. If there are several actors at the same place, only the top most actor will receive the click. If the parameter is a World then true will be returned if the mouse was clicked on the world background. If the parameter is null, then true will be returned for any click, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been clicked as explained above
mouseDragged
public static boolean mouseDragged(java.lang.Object obj)True if the mouse has been dragged on the given object. The mouse is considered to be dragged on an object if the drag started on that object - even if the mouse has since been moved outside of that object.
If the parameter is an Actor the method will only return true if the drag started on the given actor. If there are several actors at the same place, only the top most actor will receive the drag. If the parameter is a World then true will be returned if the drag action was started on the world background. If the parameter is null, then true will be returned for any drag action, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been dragged as explained above
mouseDragEnded
public static boolean mouseDragEnded(java.lang.Object obj)True if a mouse drag has ended. This happens when the mouse has been dragged and the mouse button released.
If the parameter is an Actor the method will only return true if the drag started on the given actor. If there are several actors at the same place, only the top most actor will receive the drag. If the parameter is a World then true will be returned if the drag action was started on the world background. If the parameter is null, then true will be returned for any drag action, independent of the target clicked on.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been dragged as explained above
mouseMoved
public static boolean mouseMoved(java.lang.Object obj)True if the mouse has been moved on the given object. The mouse is considered to be moved on an object if the mouse pointer is above that object.
If the parameter is an Actor the method will only return true if the move is on the given actor. If there are several actors at the same place, only the top most actor will receive the move. If the parameter is a World then true will be returned if the move was on the world background. If the parameter is null, then true will be returned for any move, independent of the target under the move location.
Parameters:
obj - Typically one of Actor, World or null
Returns:
True if the mouse has been moved as explained above
getMouseInfo
public static MouseInfo getMouseInfo()Return a mouse info object with information about the state of the mouse.
Returns:
The info about the current state of the mouse. Or null if nothing has happened with the mouse since it was last checked.